1. Field of the Invention
This invention relates to a strut type suspension for automobiles, consisting of a member for rotatably supporting a wheel, a lower control arm extending in the widthwise direction of a chassis and connected pivotably at its outer end to the support member, and a disc brake unit or an internally expansible drum brake unit provided in the wheel.
2. Description of the Prior Art
In a conventional strut type suspension of this kind, as shown in FIG. 1, a distance .delta. between the center line 5 of ground contact of a wheel 1 and an outer end fixing portion 4 of a lower control arm 3 cannot be reduced to a lower level since a space for setting a disc brake unit 2, which is positioned in the vicinity of an axis of rotation of the wheel 1, and for mounting the outer end fixing portion of the lower control arm 3 is limited; the distance .delta. is generally as long as around 50-70 mm. Let W equal a road surface input working on the wheel 1 along the center line 5 of ground contact thereof, and L a distance between the outer end fixing portion 4 of the arm 3 and an upper mounting portion 8, which is joined to a chassis 7, of a strut damper 6. The reaction force F expressed by the first equation works on the upper mounting portion 8 of the strut damper 6. EQU F=.delta.W/L (1)
Accordingly, when the distance .delta. is long, the bending moment (F.multidot.L) becomes large, so that the bending deformation occurs in a rod 9 of the strut damper 6. As a result, the rod 9 is moved frictionally in a shell 10, i.e. the former is not slid smoothly in the latter. This would give the driver a rough ride or cause noises to occur while the automobile runs. These problems are also encountered in such a strut type suspension for automobiles as having an internally expansible drum brake unit provided in a wheel 1.